Surface Integrity and Fatigue Performance of Inconel 718 in Wire Electrical Discharge Machining
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- 作者：Zhe Chen ; zhe.chen@liu.se" class="auth_mail" title="E-mail the corresponding author ; Johan Moverare ; Ru Lin Peng ; Sten Johansson
- 关键词：wire electrical discharge machining (wire EDM) ; surface integrity ; fatigue ; crack initiation ; Inconel 718
- 刊名：Procedia CIRP
- 出版年：2016
- 出版时间：2016
- 年：2016
- 卷：45
- 期：Complete
- 页码：307-310
- 全文大小：254 K
文摘
This paper presents a study to characterize the surface integrity in wire electrical discharge machining (EDM) of Inconel 718 and investigate its effect on the fatigue performance of the alloy in a four-point bending fatigue mode at room temperature. The EDM process generates a rough recast surface with multi-types of defects. Surface craters, micro-cracks and micro-voids within the recast layer have been found to be most detrimental from the point of view of fatigue as they could provide many preferential initiation sites for fatigue cracks. As a consequence, the specimens with an EDM cut surface show an approximately 30% decrease in fatigue life compared to those with a polished surface, and multiple crack origins were observed on the fracture surface. The high tensile residual stresses generated on the EDM cut surface, on the other hand, are also believed to be partly responsible for the loss in fatigue life of the alloy machined by EDM.